cc : Compute visible rects dynamically (1)

cc/trees/layer_tree_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/layer_tree_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 903 matching lines @@
   layer->SetElementId(LayerIdToElementIdForTesting(layer->id()));
 }
 
 void LayerTreeImpl::SetElementIdsForTesting() {
   LayerListIterator<LayerImpl> it(root_layer_for_testing_);
   for (; it != LayerListIterator<LayerImpl>(nullptr); ++it) {
     SetElementIdForTesting(*it);
   }
 }
 
-bool LayerTreeImpl::UpdateDrawProperties(bool update_lcd_text) {
+bool LayerTreeImpl::UpdateDrawProperties(
+    bool update_lcd_text,
+    bool force_skip_verify_visible_rect_calculations) {
   if (!needs_update_draw_properties_)
     return true;
 
   // Calling UpdateDrawProperties must clear this flag, so there can be no
   // early outs before this.
   needs_update_draw_properties_ = false;
 
   // For max_texture_size. When a new output surface is received the needs
   // update draw properties flag is set again.
   if (!layer_tree_host_impl_->compositor_frame_sink())
     return false;
 
   // Clear this after the renderer early out, as it should still be
   // possible to hit test even without a renderer.
   render_surface_layer_list_.clear();
 
   if (layer_list_.empty())
     return false;
 
   {
     base::ElapsedTimer timer;
     TRACE_EVENT2(
         "cc", "LayerTreeImpl::UpdateDrawProperties::CalculateDrawProperties",
         "IsActive", IsActiveTree(), "SourceFrameNumber", source_frame_number_);
     bool can_render_to_separate_surface =
         (!is_in_resourceless_software_draw_mode());
 
+    // We verify visible rect calculations whenever we verify clip tree
+    // calculations except when this function is explicitly passed a flag asking
+    // us to skip it.
+    bool verify_visible_rect_calculations =
+        force_skip_verify_visible_rect_calculations
+            ? false
+            : settings().verify_clip_tree_calculations;
     LayerTreeHostCommon::CalcDrawPropsImplInputs inputs(
         layer_list_[0], DrawViewportSize(),
         layer_tree_host_impl_->DrawTransform(), device_scale_factor(),
         current_page_scale_factor(), PageScaleLayer(),
         InnerViewportScrollLayer(), OuterViewportScrollLayer(),
         elastic_overscroll()->Current(IsActiveTree()),
         OverscrollElasticityLayer(), resource_provider()->max_texture_size(),
         can_render_to_separate_surface,
         settings().layer_transforms_should_scale_layer_contents,
         settings().verify_clip_tree_calculations,
+        verify_visible_rect_calculations,
         settings().verify_transform_tree_calculations,
         &render_surface_layer_list_, &property_trees_);
     LayerTreeHostCommon::CalculateDrawProperties(&inputs);
     if (const char* client_name = GetClientNameForMetrics()) {
       UMA_HISTOGRAM_COUNTS(
           base::StringPrintf(
               "Compositing.%s.LayerTreeImpl.CalculateDrawPropertiesUs",
               client_name),
           timer.Elapsed().InMicroseconds());
       UMA_HISTOGRAM_COUNTS_100(
@@ skipping 1101 matching lines @@
 
 void LayerTreeImpl::ResetAllChangeTracking() {
   layers_that_should_push_properties_.clear();
   // Iterate over all layers, including masks and replicas.
   for (auto& layer : *layers_)
     layer->ResetChangeTracking();
   property_trees_.ResetAllChangeTracking();
 }
 
 }  // namespace cc